Researchers in the fields of humanistic psychology, counseling, organizational change, and implementation science have been asking a question that is at the heart of today's early care and education quality improvement efforts: When it comes to changing one's behavior, what makes a person ready to change? Although the concept of readiness to change is widely integrated in the field of health behavior change, it has not been applied to the field of early childhood educator professional development. This article describes what may be the first study of early childhood educators' readiness to change their practices, and it presents a theoretical framework for understanding readiness to change in the context of early care and education. Findings of the study demonstrate that over one third of educators receiving mentoring services were rated by their mentors as "not ready to change" as measured by the Stage of Change Scale 1.0. Qualitative analyses of interviews and focus groups with mentors identify common features of educators who were not ready to change as well as mentors' strategies and challenges in working with these educators. The article concludes with recommendations for policy and practice. (Contains 1 figure.)